The ω-diphenylurea derivatives are known as the compounds with c-RAF kinase inhibition activity. For example, W02000/042012 disclosed a class of co-carboxyl-aryl-substituted diphenylurea and the use thereof for treating cancer and related diseases.
Initially, ω-diphenylurea compounds, such as Sorafenib, were firstly found as the inhibitor of c-RAF kinases. The other studies had shown that they could also inhibit the MEK and ERK signal transduction pathways and activities of tyrosine kinases including vascular endothelial growth factor receptor-2 (VEGFR-2), vascular endothelial growth factor receptor-3 (VEGFR-3), and platelet-derived growth factor receptor-β (PDGFR-β) (Curr Pharm Des 2002, 8, 2255-2257). Therefore, they were called multi-kinase inhibitors that resulted in dual anti-tumor effects.
Sorafenib (trade name Nexavar), a novel oral multi-kinase inhibitor, was developed by Bayer and Onyx. In December 2005, based on its outstanding performance in phase III clinical trials for advanced renal cell carcinoma, Sorafenib was approved by FDA for treating advanced renal cell carcinoma, and marketed in China in November 2006. However, Sorafenib has various side-effects, such as hypertension, weight loss, rash and so on.
However, the current procedure for preparing deuterated diphenylurea compounds is immature, and has some disadvantages, such as high-cost, low-yield, low-purity or difficulties in separation and so on. Therefore, novel and highly efficient procedures for preparing diphenylurea compounds are needed to be developed.